Michael Piwowar, then a nominee to the SEC, speaks during a Senate Banking Committee nominations hearing in Washington in June.

Michael Piwowar joined the Securities and Exchange Commission a little over a month ago but he’s already registering unusually blunt objections to some of the priorities at Wall Street’s top regulator.

Mr. Piwowar, a new Republican on the five-member commission, said at his first open commission meeting Wednesday the agency is wasting its time and resources on a rule that runs counter to its core mission.

“The commission should not be spending any of its limited resources on any rulemaking that unambiguously harms investors, negatively affects competition, promotes inefficiencies and restricts capital formation,” Mr. Piwowar said.

At issue is a proposal to require public companies to disclose the ratio between CEO compensation and the median pay of rank-and-file employees. Median pay is the point on the income scale at which half the employees earn more and half earn less.

Labor unions and other supporters say requiring companies to publish the ratio will pressure corporate boards to slow pay increases for chief executives at firms with significant or growing gaps. The rule is a requirement of the 2010 Dodd-Frank law.

Mr. Piwowar, a former Senate aide to Sen. Michael Crapo (R., Idaho), said supporters want to use the ratio to “shame” CEOs but “the shame from this rule should not be put on the CEOs, it should be put on the five of us who would be voting on this proposal today.”

SEC Chairman Mary Jo White disputed Mr. Piwowar’s concerns prior to the vote, saying the agency “is trying to move quickly but we are being responsible.” She added that the rules before the commission Wednesday are Dodd-Frank mandates that “have been worked on and thought about by the staff for a long time– actually years, in fact.”

The agency approved the measure by a vote of 3-to-2 along party lines. The SEC is collecting comment on the proposal for 60 days and then has to vote on it again before it can go into effect.

About Washington Wire

Washington Wire is one of the oldest standing features in American journalism. Since the Wire launched on Sept. 20, 1940, the Journal has offered readers an informal look at the capital. Now online, the Wire provides a succession of glimpses at what’s happening behind hot stories and warnings of what to watch for in the days ahead. The Wire is led by Reid J. Epstein, with contributions from the rest of the bureau. Washington Wire now also includes Think Tank, our home for outside analysis from policy and political thinkers.